8.1)

\

Amplitude:

\

 The Oscilloscope displays a sine wave having \"\" vertical divisions and \"\" horizontal divisions.

\

The vertical amplifier scale is 2 V/div.

\

The horizontal scale is \"\".

\

The Amplitude of a sine wave is magnitude of maximum voltage to reference line.

\

Therefore, consider \"\" vertical divisions from reference line to maximum value.

\

\"\"

\

Amplitude 6 V.

\

Step 2:

\

8.2)

\

The peak-to-peak value: \"\".

\

\"\" is the peak amplitude of the waveform.

\

\"\"

\

Substitute \"\" in the above expression.

\

\"\"

\

The peak-to-peak voltage value is 12 V.

\

Step 3:

\

8.3)

\

Period:Time taken by the wave to complete one full cycle.

\

The time period of a sine wave is number of divisions \"image\" horizontal scale.

\

\"\"

\

Time period of the wave is \"\".

\

Frequency: \"\".

\

\"\"

\

Frequency of the wave is 8.33 khz. 

\

Step 4:

\

Average DC voltage value is 0.637 times of its peak value. 

\

\"\".

\

Substitute \"\" in the above expression.

\

\"\"

\

Average DC voltage value is 3.822 V.

\

 

\

 

\

8.4)

\

Find the frequency of the waveform.

\

Frequency: \"\".

\

\"\"

\

\"\".

\

Frequency of the wave is 125 khz.

\

Step 5:

\

8.5)

\

Find the RMS value of the waveform.

\

RMS voltage is defined as \"\".

\

Substitute \"\" in the above expression.

\

\"\"

\

RMS voltage is 1.0606 V.

\

 

\

 

\

 

\

7.1)

\

Three factors of capacitor influence capacitance of a capacitive transducers :

\

(1) PLATE AREA :

\

Greater plate area gives greater capacitance and less plate area gives less capacitance.

\

Larger plate area results in more field flux for a given field force.

\

(2) PLATE SPACING :

\

Large plate spacing gives less capacitance and closer plate spacing gives greater capacitance.

\

Closer spacing results in a greater field force, which results in a greater field flux for any given voltage applied across the plates.

\

(3) DIELECTRIC MATERIAL :

\

Greater permittivity of the dielectric gives greater capacitance and less permittivity of the dielectric gives less capacitance.

\

Materials with a greater permittivity allow for more field flux, so greater collected charge, for any given amount of field force.

\

 

\

7.2)

\

The speed of a rotation shaft is measured by using Tachometer.

\

Tachometer :

\

Tachometer generators are electromechanical devices which output a voltage proportional to their shaft speed. They are used to measure the speed of motors, engines, and other rotational devices.

\

Tachometer Diagram :

\

\"\"

\

Operation of Tachometer :

\

These devices use a rotating armature, one end of which is attached to a machine shaft, to measure rotational speed.

\

The armature rotates within a fixed magnetic field, so that its rotation induces electromotive force proportional to the shaft speed.

\

The armature contacts are connected to a voltmeter circuit, which converts the voltage into a speed value.

\

In this particular device, the commutator between the armature and voltmeter circuit serves to convert internally generated AC voltage into DC for compatibility with the voltmeter.

\

Small permanent magnet motors can be used as tachometer generators in some applications.

\

 

\